I suppose it's worth pointing out that lots of password vault apps available for mobile devices actually do really dumb things that don't secure your passwords very well. Paid or free, quite a few of them make some really elementary crypto mistakes.

A few researchers from Elcomsoft sum it up well in this white paper:

http://www.elcomsoft.com/WP/BH-EU-2012-WP.pdf

There's lots of crypto-geek stuff in there, but if you're even moderately interested in the particulars, it's well worth your time.

Long story short, mobile password safes often have serious problems if an even moderately skilled and motivated attacker steals or confiscates your phone.

To echo what a few others have said, I highly recommend not using the same password value for more than one account or using your Facebook/Google/whatever account to authenticate to other services.

Thanks for letting me blather.

-p